Automatic road signal



Nov. 6, 1934. Y H. c. WILLIAMS AUTOMATIC ROAD SIGNAL Original Filed Oct.15, 1950 \.3nventor Patented Nov. 6, 1934 UNITED STATES PATE OFFICEApplication October 15, 1930, Serial No. 488,922 Renewed April 9, 1934 2Claims.

The present invention relates to signaling apparatus and has specialreference to a signal to be placed at road intersections such as where aside road crossesv a main highway, railways, and the like.

One of the primary objects of the invention resides in providing such adevice which may be operated automatically by a vehicle traveling on aside road toward a main highway, but which will not be aiected by avehicle when traveling on the side road in a direction away from themain highway.

Another object of the-invention consists in providing such a devicewhich is durable and reliable in operation and yet which is of suchsimple construction as to be inexpensive in manufacture.

Other'objects and advantages of the invention will be apparent from thefollowing description when taken in connection with the accomlpanyingdrawing, in which Figure 1 is a perspective view of the completeapparatus installed at a'crossroad.

Figure 2 is a transverse sectional view taken on line 2--2 of Figure 1;and

Figure 3 is a vertical sectional View through one of the damping orretarding cylinders.

Referring to the drawing in greater detail, the numeral 1 indicates amain highway and the numeral 2 a side road entering the main highway, atthe intersection ci which is mounted a signal post 3 on which issuspended signals 4 and 5. The signal 4 may be of the conventional typeof visual electric signal provided with red, green, or yellow lights,while the signal 5 is an audible alarm, preferably an electric gong.Also, if desired, an electric horn 6 may be employed. It will beunderstood, of course, that any one or all of these various types ofsignal devices may be employed as found desirable.

The signaling devices are operated from batteries 7 in an electriccircuit 8. Also in this circuit is a control switch 9. This switch isoperated by means of an arm 10 preferably of channel iron and extendingentirely across the roadway. This arm is pivoted to a second channeliron 11 as indicated by the numeral 11 and is normally held in itsraised position by a dashpot or retarding device l2.

The dashpot is shown in detail in Fig. 3 and comprises a cylinder inwhich is mounted a piston which is normally held at the upper end of thecylinder by means of a coil spring 13. This piston comprises aperforated metal disc 14, a flexible perforated leather disc 15 mountedthereon, and ka. rigid but loosely mounted imperforate metal disc 16disposed thereabove. The perforat-v ed discs 14 and 15 are of a diameterequal to that of the cylinder 12, while the disc 16 is of slightly lessdiameter than the cylinder. These three disc-like elements which formthe piston `are mounted on the lower end of a piston rod 17 which is inturn pivoted to thecross arm 10 as indicated by the numeral 18.

The cylinder 12 has a pipe connection 19 at its upper end which extendsdownwardly and re-enters the lower end of the cylinder, as indicated bythe numeral 20. Intermediate the ends 19 and 20 of this pipe is anadjustable valve 21 by means of which the rate of passage of the fluidthrough the pipe 19--20 may be readily adjusted. Any desiredfiuid may beplaced within the cylinder 12 and will, through the action of the pistonjust described and the valve 2l, retard the return of the arm l0 to itselevated position.

The descent of the arm 10 by reason of the pressure of the wheels of avehicle passing along the roadway 2 is permitted by reason of theapertures in the discs 14 and 15, and the loose mounting of the disc 16,which permit a practically free flow of the fluid past the piston. Theupward stroke of the arm 10, however, is retarded by reason of the factthat the disc 16 will close 01T the apertures in the discs 14 and 15 andthus cause the fluid in the upper end of the cylinder to pass outwardlythrough pipe 19, valve 21, and pipe 20, to the lower end of thecylinder. The time required for the ilow of fluid from the top to thebottom of the cylinder may, of course, be regulated by adjustment of thevalve 21, thereby definitely determining the period during which theswitch 9 will be closed by reason of the depressed position of the arm10.

With the apparatus as thus far described, it will be obvious that thesignals 4, 5 or 6 would be operatedeach time a vehicle passed over thearm 10 regardless of whether the vehicle was traveling toward the mainhighway l or away from the main highway. In order to permit an operationof the signaling apparatus only when a vehicle is traveling toward theintersection of the main highway, I have provided a controllingmechanism for the arm 10 which comprises a second arm 30 of channel ironpivoted at 31 toa channel iron 32. 'Ihese members are substantiallyidentical with the members 10 and 11 heretofore referred to, and arearranged in parallel relation therewith, preferably at a distancegreater than the length of a vehicle, from the members 10 and 11, and,of course, are placed at that side of the members 10 and 11 remote fromthe main highway 1.

Pivotally mounted on the end of the channel member 32 is a bell cranklever 33 which has a pin and slot connection with a slidable rod 34 andthe free end of the arm 30. This rod extends across the space betweenthe arms 10 and 30, and has its free end slidably mounted in a bearing35 on the end of the channel member 11. When the parts are in thepositions shown in Fig. 1, it will be observed that the rod 35 extendsbetween the free end of arm 10 and the channel member l1, therebypreventing the depression of the arm 10 and consequently preventing theclosing of the electric switch 9.

For the purpose of suitably timing the operation of the arm 30 so thatthe rod 34 will not be returned to its locking position prior to thereturning of the arm 10 to its uppermost position, a dashpot or dampingdevice 36 similar in all respects to the dash-pct 12 is connected to thefree end of thearm 30. With this construction, it is apparent that ifthe two arms 30 and l0 are depressed by a vehicle approaching theintersection of the roadways, the return movement of the4 arm 30 whichis iirst depressed will be retarded through the medium of the dashpot36, just as the movement of the arm 10 is retarded by the dashpot 12.Hence the rod 34 will not be projected between the channel members 10and 11 until such time as the arm 10 is permitted to rise toitsuppermost position `by the expansion of the coil spring i3 and thetravel of the iluid through the pipes 19--20 and the fvalve 21.

The operation of the device has been fully described in connection withthe description of the various details of construction, but a brieiresume of its operation will now be given.

If a vehicle turns from the main highway 1 into the cross road2 itspassage over the arm 10 will not aiect the signal in any way whatever,inasmuch as the rod 34 will have its end `disposed beneath the arm 10and thus prevent the closing of the switch 9. As the vehicle continuesonward away from the road 1 and passes over the arm 30 it will depressthe latter and withdraw the arm 34 but inasmuch as it has already passedover the arm 10, the signals will not be operated.

When a vehicle is traveling toward the main highway 1, however, it willnrst cause the withdrawal of the rod 34 by reason of depressing the arm30 and in its continued movement it will depress the arm 10therebyclosing the switch and operating the visual signal 4 so as to eliminatethe red lights directed up and down the main highway, and of course,changing the lighten the wide road from red to yellow. Also, thismovement of the vehicle will sound the alarms 5 and 6 if they areprovided in the circuit. The alarms thus set in operation will remain-inoperation until a substantial ow of the fluid from the upper end of thecylinder 12 to the lower end thereof has taken place, thereby permittingthe rod 17 and arm 10 to rise and open the switch 9, at which time thevisual signal will return to its normal condition showing a red light onthe side road and the yellow light on the main road, and the audiblesignals will be silenced.

While the specific construction of dashpot for retarding or damping theoscillations of the members l10 and 30 has been described, it will beobvious that any preferred means for slowing down or retarding theupward movements of these members may be employed.

From the foregoing description taken in connection with the accompanyingdrawing, it will be apparent that I have devised an exceedingly simpleconstruction of signal for roadway intersections, which is both reliableand durable in operation, and which is so designed as to avoid anypossibility ofthe signal being operated except at such time as isynecessary, namely, when a vehicle is traveling onto the main highway.

In accordance with the patent statutes I have described what I nowbelieve to be the preferred form of the invention, but as various minorchanges may be made in the details of construction without departingfrom the essence of the invention, it is intended that all such beincluded within the scope of the appended claims.

What I claim is:

1. In an automatic signaling device for roadways, a pair of suitablyspaced, vehicle-operated arms mounted across a roadway, springs normallyholding said arms in elevated positions, a rod normally disposed beneathone of said arms for locking` it in raised position, means forsupporting the rod, means associated with the other arm for moving saidrod to release the rst-mentioned arm whereby the rst-mentioned arm maybe depressed against the action of said springs, a road device capableof actuation and means operated by depression of ther rst-inentioned armfor actuating said road device.

2. In an automatic signaling device for roadways, a pair of suitablyspaced, vehicle-operated arms mounted across a roadway, springsnormally` holding said arms in elevated positions, a rod normallydisposed beneath one of said arms for locking it in raised position,means for supporting the rod, means associated with the other arm formoving said rod to release the firstmentioned arm whereby theinst-mentioned arm may be depressed against the action of said springs,a road device capable of actuation, means operated by depression of theiirst-mentioned arm for actuating said road device, and retardingdevicesior controlling the return movements of said arms.

AHOWARD C. WILLIAMS.

